Combined vacuum tube and relay



June 25, 1929. CLARK r AL 1,718,528

COIBINED VACUUM TUBE AND RELAY Filed Nov. 7, 1925 AT ORNEY Patented June 25, 1929.

UNITED STATES PATENT OFFICE.

THOMAS E. CLARK AND JAMES E. CLARK, OF DETROIT, MICHIGAN, ASSIGNOBS TO CONTINUOUS TRAIN CONTROL CORPORATION, 013 DETROIT, MICHIGAN, A CORPO- RATION OF MICHIGAN.

COMBINED VACUUM TUBE AND RELAY.

Application filed November 7, 1925. Serial No. 67,495.

shown means for propagating electromagnetic waves of two different wave lengths in the rails of each block of a railway track, the length or the absence of the waves indicating the occupancy of the next three blocks of track in advance to a train in one of such controlled blocks. We have arbitrarily assumed that current of a longer wave length indicated clear conditions, that is, that the next three blocks in advance of that occupied by the train were unoccupied; that a shorter wave length indicated caution conditions, that is, that the third block in advance was occupied and the two in advance were unoccupied; and an absence of current indicated danger conditions, that is, that one or both of the next two blocks in advance was occupied.

lVe also showed instrumentalities mounted on the locomotive, including loop collector coils influenced by the lines of force of this electro-magnetic wave flux and means for utilizing the currents produced by such action, in combination with a polar relay which was affected by such currents flowing to control the air brakes of the locomotive and the signal lamps in the cab.

Our present invention relates to the instrumentalities on the locomotive connected to the loop collector coils, including the p0= lar neutral relay, and its object is to provide a structure of this character which shall be reliable in its operation, which will withstand the shocks and jars incident to railway travel and which shall be simple in construction.

This invention consists in the details of construction illustrated in the accompanying drawings and particularly pointed out in the claims.

In the drawings, Fig. l is a diagram of this improved train control apparatus embodying power driven current sources. F ig. 2 is a'diagram of a portion thereof showing batteries as the sources of current.

Similar reference characters refer to like parts throughout both views.

As the elements which go to make up this control mechanism are all well known, none are detailed. The polar neutral relay employed is of well known construction and we have indicated its coils 18 and 21, its neutral armatures a and b and its polar armature c. The current to energize this relay and electron tubes 3 and 4 is primarily obtained from the generator G which is usually pro vided to furnish current for the locomotive headlight and the cab lamps, and this generator is connected to the rotary transformer or dynamotor 5 by means of wires 6 and 7. Vs may assume that the current from the generator is of twenty-eight volts and the current from the dynamotor is of about three hundred volts.

The filaments 33 and 43 of the tubes are heated by current from the generator passmg over the wires 6, 8 and 9, the filament 33, wire 10, the filament 43, the wires 11 and 12, the resistance 14, and wires 15, 16 and 7 to the generator.

WVhile this current is passing, electron fiow occurs from the filament 33 to the plate 31 and from the filament 43 to the plate 41. The currentfrom the dynamotor passes over wires 16 and 15, resistance 14, wires 12 and 11, filament 43 across the tube 4 to plate 41, over wire 17 to coil 18 and wire 19 to the dynamotor, and also over Wire 10, filament 33, across tube 3 to plate 31, over wire 20 to coil 21 and over wire 19 to the dynamotor.

When the electro-magnetic flux passes to both coils simultaneously and as they are so wound that their lower ends are of the same polarity, they neutralize each other and have no attraction for the armatures a and b, which drop, and current flows from the generator over wires 6, 8 and 23 to the red lamp 52, then over wire 13, armature b, and wires 22, 15, 16 and 7 to the generator. This ocours when there is no control current in the rails or when the next or second block ahead is occupied, that is, when danger conditions exist in the track ahead.

lVhen one of the coils 18 or 21 is energized and the neutral armatures a and b are attracted, they close the circuit from the generator G over wires 6, 8, 23 and 24, armature (a, wire 25, solenoid 26, and wires 15, 16 and 7 back to the generator. As explainedin said prior application, this solenoid is connected to an air valve 28 which connects to the train line pipe of the brake mechanism and is held closed by the energized solenoid. But when no current passes to this solenoid, as when both coils 18 and 21 are energized or both (lo-energized, the valve opens and the brakes are set unless other means are employed to energize the solenoid as explained in said application. But such means are outside the present invention.

When both coils 18 and 21 are energized,

or both de-energizcd, their action 011 the polar armature c is balanced and the armature has no function because no current passesto it.

The control circuits comprise loop collector coils 34 and 44, wires 35 and 45 leacing therefrom to the grid condensers 36 and 46 and to the grids 32 and 42, and wires 37 and 47 leading to the wires 9 and 11 respectively which connect to the filaments of the tubes. An adjustable condenser 38 shunts the wires 35 and 37 and adjusts the receiving circuit to. predetermined wave lengths, while an adjustable condenser 48 shunts the wires 45 and 47.

When electro-magnetic waves are propagated in the rails 1 and 2, the flux flows spirally along the rails of the block and these lines of force pass in part to the loop collector coils 34 and 44 as. the locomotive carrying them moves along the track. These coils are part of the receiving circuit connected to the grids 32and 42. It is a characteristic of these electron tubes that when such lines of electromagnetic wave flux are flowing in these collector coils, the grids have a strong negative potential. .VVhen the grid of an electron tube is charged to a sufiiciently high negative po tential relative to the filament by an eX- ternal electro-motive-force, such as may be supplied by the electro-magnetic wave flux flowing in the collector coils 34 and 44, the flow of electrons from the filament to the plate is substantially obstructed and few electrons pass between the filament and plate.

We now assume that electro-magnetic wave energy of about 20,000-meter wave length is propagated in the rails ofthe block occupied by the locomotive equipped with the instrumentalities above described, and that. these are being propagated under clear conditions of that block of track. The loop collector coil circuit connected to the grid of tube 4 causes this grid to.become negatively charged to decrease the electrons flowing from filament 43 to plate 41 and the coil 18 becomes de-energized. The coil 18 having no opposing effect, the coil 21 causes the armature c to swing clockwise and the armatures a and Z) to be elevated. The path of the current to the solenoid 26 has already been described. Current also flows from the wire 23 to green lamp 550 and over wire 53, armature 0, wire 54, armature Z) and wires 22, 15, 16 and 7 to the generator. The green lamp in the cab indicates that the three blocks in advance are unoccupied.

While we have shown the coils 34 and 44 over different rails, it should be understood that they maybe over the same rails as the track circuit comprises the two lines of rails of the block and the same current is in both. But the two loop collector coil circuits are tuned for different wave lengths by the variable condensers 38 and 48.

When current whose wave length is 15,- 000 meters is flowing in the track circuit, the grid 32 of tube 3 accumulates the negative potential and the coil 21 becomes de-energized, resulting in the armature c swinging counter clockwise and current passing to the yellow or caution lamp 51,

and thence over wire 55 to the polar armature c, this lamp indicating that the third block in advance is occupied.

Should a tube break or become inoperative for any reason, no current will flow through its filament or through the filament of the other tube. The coils 18 and 21 would immediately become de-energized, the armatures a and 6 would drop, the red lamp 52 would receive current and the solenoid 26 would become de-energized and permit the by those skilled in the art without departing from the spirit of our invention as set forth in the following claims.

. lVeclaim:

1. In combination, a polar relay comprising a pair of coils and a polar armature adapted to be swung to either of two positions as one or the other coil is energized, a source of current, and an electron tube for each coil through which said coil receives electro motive-force from said source of current, and means connected to the grid of each tube for intercepting electro-magnetic wave flux whereby said grid is so charged as to prevent the passage of electro-motiveforce from said source of current to the coil.

2. In combination, a polar relay comprising a pair of coils and a polar armature adapted to be swung to either of two positions as one or the other coil is energized, a.

source of current, an electron tube for each whereby said grid is so charged as to prevent the passage of electro-motive-force from sald source of current to the coil, 9.- neutral armature for said relay adapted to beat- CIl tracted when either coil is energized, two signal lamps and circuits therefor controlled by the neut'al and polar armatures, said coils adapted to neutralize each other to become inactive when energized simultaneously, a third signal lamp, and a circuit therefor adapted to be closed when said coils neutralize each other to drop the neutral armature.

3. In combination, a polar relay embodying a pair of coils, an electron tube connected to each coil, a current source to heat the filaments of the tubes, a second current source to supply current to said tubes and through them to the relay, and means embodying a source of electro-magnetic fiux to render the tubes non-conductive.

4. In combination, a polar relay embodying a pair of coils, an electron tube connected to each coil, a current source to heat the filaments of the tubes, a second current source to supply current to said tubes and through them to the relay, and means embodying a source of electromagnetic flux and receiving circuits to render the tubes non-conductive, said circuits comprising means to tune said circuits to electro-magnetic Waves of predetermined lengths.

5. In combination, a polar relay embodying a pair of coils, an electron tube connected to each coil, a current source to heat the filaments of the tubes, a second current source to supply current to said tubes and through them to the relay, means embodying a source of electro-magnetic flux and receiving circuits to render the tubes nonconductive, said circuits comprising adjustable condensers to tune said circuits to electro-magnetic waves of predetermined lengths and condensers and grid leaks connecting to the grids of said tubes to produce sufiicient negative potential therein to obstruct the passage of electrons from the filaments to the plates of the tubes.

6. In combination with a current source and a polar relay embodying a pair of coils, a vacuum tube for each coil and embodying a plate connected to the coil, a filament connected, to the current source and from which electrons pass to the plate, and a grid between the filament and plate; and means to produce negative potential in said grid to obstruct the passage of the electrons comprising a circuit including a coil adapted to cut lines of electro-magnetic flux.

7. In combination with a current source and a polar rela embodying a pair of coils, a vacuum tube or each coil and embodying a plate connected to the coil, a filament connected to the current source and from which electrons pass to the plate, and a grid between the filament and plate; means to produce negative potential in said grid to obstruct the passage of the electrons comprising a circuit including a coil adapted to cut lines of electro-magnetic flux; and an adj ustable condenser to tune the circuit to electro-magnetic waves of predetermined length.

8. In combination with a current source and a polar relay embodying a pair of coils, a vacuum tube for each coil and embodying a plate connected to the coil, a filament connected to the current source and from which electrons pass to the plate, and a grid between the filament and plate; means to produce negative potential in said grid to obstruct the passage of the electrons comprising a circuit including a coil adapted to cut lines of electro-magnetic flux and means to rectify said flux to produce such negative potential.

THOMAS E. CLARK. JAMES E. CLARK. 

